The claimed invention relates generally to data storage devices and more particularly, but not by way of limitation, to minimizing the ingress of atmospheric contaminants within a data storage device housing.
Digital data storage devices, such as disc drives, are used in computer based systems to store and retrieve large amounts of user data. A typical data storage device includes an environmentally controlled housing in which one or more data recording discs are rotated during operation.
Data are written to and retrieved from the discs by a corresponding number of data transducing heads supported by a moveable actuator. Control electronics for the device are typically supported on a printed circuit board (PCB) mounted to an exterior surface of the housing. A flex circuit assembly projects through the housing to establish the requisite communication paths between the actuator and the PCB and to facilitate movement of the actuator within the housing.
It is desirable to minimize the presence of particulate contamination within a data storage device housing, as such contamination can adversely affect data storage, transfer performance and reliability. Data storage housings are typically sealed using gaskets and similar features to prevent the ingress of atmospheric contaminants.
It is difficult and cost prohibitive to completely seal a drive to prevent air infiltration. A desirable approach is to design in a leak with appropriate filtration such that, for practical purposes, all of the air transports through a known leak path.
A diffusion path is typically formed through a housing wall and provides a elongated, narrow channel which permits fluidic flow and lessens the mass transport per unit time due to diffusion. Filters are incorporated at the end of diffusion paths to further adsorb contaminants and prevent the ingress of such contaminants into the housing.
With continued demand for higher performance, lower cost data storage devices, there remains a continual need for improved approaches to controlling the ingress of particulate and chemical contamination into a data storage device housing. It is to such improvements that the claimed invention is directed.
In accordance with preferred embodiments, a data storage device comprises a housing which supports a rotatable data recording surface and an actuator which controllably moves a data transducing head across the recording surface. A printed circuit board (PCB) provides control electronics for the data storage device, and is preferably mounted to an exterior of the housing.
A flex circuit assembly facilitates electrical communication between the actuator and the printed circuit board. The flex circuit assembly includes a laminated flex circuit and a flex circuit bracket. The flex circuit bracket supports the flex circuit assembly and establishes a diffusion path between the interior of the housing and an external environment to equalize interior and external atmospheric pressures while restricting ingress of contaminants into the interior of the housing.
The flex circuit bracket includes a rigid plate having a diffusion path aperture and opposing exterior and interior surfaces. The flex circuit bracket further includes a laminated flex circuit comprising a flexible, electrically insulative layer which embeds a longitudinally extending, electrically conductive trace.
The flex circuit includes a web portion and an extended portion. The extended portion is configured to form a dynamic loop between the web portion and the actuator. The web portion is affixed to the exterior surface of the plate so that a portion of the web portion extends adjacent the diffusion path aperture to form the diffusion path.
In another preferred embodiment, the plate is characterized as an upper plate and the flex circuit bracket further comprises a second, lower plate with a diffusion path aperture and opposing interior and exterior surfaces. The web portion is attached to the exterior surface of the lower plate, after which the web portion is preferably folded to bring the interior surfaces of the plates into mutual facing alignment and to align the respective diffusion path apertures of the plates. A connector is preferably affixed to the web portion and placed in electrical communication with the electrically conductive trace.
The method for fabricating the flex circuit bracket preferably comprises steps of providing a rigid plate with a diffusion path aperture and opposing interior and exterior surfaces, providing a flex circuit with a web portion and an extended portion, and affixing the web portion of the flex circuit to the exterior surface the plate to form the diffusion path.
Additionally, the method preferably comprises providing a second plate and affixing the web portion to both plates and folding the web portion to align the plates and complete the bracket.
The bracket is preferably mounted to an interior wall of the housing over an aperture through which the connector extends to mate with the disc drive PCB. The diffusion path thus extends from the external environment, through the housing aperture, through the plate(s) and into the interior of the housing. A chemical adsorbent filter can be advantageously placed over the opening so that fluids passing from the bracket diffuse through the filter before moving to the interior of the housing.
These and various other features and advantages which characterize the claimed invention will become apparent upon reading the following detailed description and upon reviewing the associated drawings.